this version has the following changes:

fixes:

- modifiedEvent: in case a change is detected, it asks for confirmation
to avoid losses.

adds:

- new analyze tool: check if all nodes have at least one connection with
each other
- new tools:
1) invert connections, makes the connections complementary to the
current one
2) make connections, connects non-connected nodes to each other.
- select images/change images of the nodes via context menu. new images
  can be added into src/com/mxgraph/examples/swing/images with PNG
  extension to take part

src/com/mxgraph/analysis/mxGraphStructure.java

@@ -43,6 +43,9 @@ public static boolean isConnected(mxAnalysisGraph aGraph)
 
 		//data preparation
 		int connectedVertices = 1;
+		if(vertexNum < 1) {
+			return true;
+		}
 		int[] visited = new int[vertexNum];
 		visited[0] = 1;
 

src/com/mxgraph/app/designer/properties/editor.properties

@@ -33,6 +33,9 @@ pageLayout=Page Layout
 antialias=Antialias
 exitText=Are you sure you want to exit this program?
 analyze=Analyze
+tools=Tools
+makeComplementary=Invert connections
+makeConnections=Make missing connections
 measureText=Measure distance between nodes
 notConnected=Some vertices are not connected!
 emptyValue=Entered {1} value is not valid!
@@ -50,6 +53,10 @@ type=Type:
 cancel=Cancel
 calculate=Calculate
 totalDistance=Total minimal distance is:
+isConnected=Check if all nodes are connected
+diagramStatus=All nodes are {1}
+connected=connected.
+notconnected=not connected.
 grid=Grid
 rulers=Rulers
 zoom=Zoom
@@ -116,6 +123,7 @@ west=West
 rotateLabel=Rotate Label
 rotation=Rotation
 image=Image
+more=More
 style=Style
 shape=Shape
 home=Home
@@ -217,3 +225,4 @@ backupRecommended=Backup in ETD Format Recommended
 loseDetails=Saving in Plain Topology Format removes all cosmetic information. Hence, it cannot be opened with Topology Editor again.\nConsider saving a copy as an ETD File.
 noLayout=Layout unavailable
 error=Error
+information=Information

src/com/mxgraph/examples/swing/editor/BasicGraphEditor.java

@@ -1,6 +1,7 @@
 package com.mxgraph.examples.swing.editor;
 
 import java.awt.BorderLayout;
+import java.awt.Image;
 import java.awt.Point;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
@@ -642,7 +643,7 @@ public Action bind(String name, final Action action)
 	public Action bind(String name, final Action action, String iconUrl)
 	{
 		AbstractAction newAction = new AbstractAction(name, (iconUrl != null) ? new ImageIcon(
-				BasicGraphEditor.class.getResource(iconUrl)) : null)
+				new ImageIcon(BasicGraphEditor.class.getResource(iconUrl)).getImage().getScaledInstance(16, 16, Image.SCALE_DEFAULT)) : null)
 		{
 			public void actionPerformed(ActionEvent e)
 			{